1. Field of the Invention
The present invention relates to an insertion type buckle comprising a housing-shaped buckle main body and an insertion body having leg portions for an insertion and more particularly, relates to a belt tightening buckle ordinarily used for clothing, bag, sport goods and the like.
2. Description of the Related Art
In a conventional insertion type buckle comprising the housing-shaped buckle main body 101 and the insertion body 102 having the insertion leg portions 131 on both right and left sides of the insertion body 102, as shown in FIG. 12, a pair of wall bodies 150 are provided longitudinally in a center of an inner face of a housing 120 of the buckle main body 101 between upper and lower plates of the buckle main body 101, and these wall bodies 150 form a wedge-shaped guide groove 105 in which its opening side is wide while its deep side is narrowed. A wedge-shaped small protrusion 151 projecting into the guide groove 105 is formed in a deep portion of this guide groove 105 and then a small and shallow wedge-shaped guide groove 152 is provided recessedly on the opening side of the guide groove 105. In the insertion body 102, a guide member 106, which can be inserted into the guide groove 105, is provided in a center of its proximal lever 130 such that it is projected forward, and a wedge-shaped small guide groove 153 which can be fitted to the small protrusion 151 provided on the buckle main body 101 is provided at a front end of the guide member 106. Further, a wedge-shaped small protrusion 154 which can be fitted to the small guide groove 152 provided in the guide groove 105 of the buckle main body 101 is provided on each of both front and rear surfaces of the guide member 106 at its proximal portion such that both of them overlap each other. As a result, this insertion type buckle have three positions in which the respective members engage each other firmly.
Further, according to another insertion type buckle, as shown in FIG. 13, a pair of guide pieces 255 are provided along the longitudinal direction in the center of the inner face of the housing 220 of the buckle main body 201 such that they are projected inward, so that a concave guide groove 205 is provided and then a guide lever 206 having a H-shaped cross section is provided protrudedly in the center of the proximal lever 230 and the guide lever 206 can be inserted into the guide groove 205.
Patent document 1: Japanese Patent Application Laid-Open No. 8-131215
Patent document 2: U.S. Pat. No. 5,794,316
Because in the insertion type buckle shown in FIG. 12, the guide groove 105, small protrusion 151 and small guide groove 152 provided in a housing 120 of the buckle main body 101 are all wedge-shaped and all the guide member 106, small guide groove 153 and small protrusion 154 disposed in the insertion body 102 are wedge-shaped, the buckle main body 101 and insertion body 102 are engaged with each other in a specified insertion range so that the position of the buckle in the longitudinal direction can be controlled. However, because there is no mechanism for restricting a swing of the buckle in the direction to front and rear surfaces, when the insertion leg portions 131 and guide member 106 of the insertion body 102 are inserted into the housing 120 of the buckle main body 101, looseness occurs and if this buckle is used in a bag or the like, impact sound or vibration sound is generated so as to make user feel discomfort.
Further, in case of the insertion type buckle shown in FIG. 13, when the guide lever 206 of the insertion body 202 is inserted into the guide groove 205 formed in the inner face of the housing 220 of the buckle main body 201, it is necessary to provide an allowance between the guide groove 205 and the guide lever 206 so as to secure a gap in order to insert the guide lever 206 into the guide groove 205 smoothly, because the thickness of the guide lever 206 is constant. However if the gap is provided, looseness occurs so that vibration sound is generated. Further, if the guide lever 206 is formed thick, when the guide lever 206 of the insertion body 202 is inserted into the housing 220 of the buckle main body 201, there is such a problem that the insertion operation cannot be performed smoothly because friction resistance is large.